| Инд. авторы: | Likhacheva A.Y., Goryainov S.V., Bul'bak T.A. |
| Заглавие: | An X-ray diffraction study of the pressure-induced hydration in cordierite at 4-5 GPa |
| Библ. ссылка: | Likhacheva A.Y., Goryainov S.V., Bul'bak T.A. An X-ray diffraction study of the pressure-induced hydration in cordierite at 4-5 GPa // American Mineralogist. - 2013. - Vol.98. - Iss. 1. - P.181-186. - ISSN 0003-004X. - EISSN 1945-3027. |
| Внешние системы: | DOI: 10.2138/am.2013.4199; SCOPUS: 2-s2.0-84872030831; WoS: 000313148500017; |
| Реферат: | eng: The elastic and structural behavior of natural cordierite compressed in aqueous medium up to 6 GPa was studied by means of in situ synchrotron powder diffraction with a diamond-anvil cell. In the range between 1-4 GPa the elastic behavior is regular and slightly anisotropic, with linear compressibilities beta(a):beta(b):beta(c) = 4:4:5, the most rigid a-b plane coinciding with the orientation of 6-membered rings. A distinct decrease of compressibility in the range of 4-5 GPa indicates a pressure-induced hydration (PIH), which is confirmed by the structure refinements. The addition of about 60% of the initial water content into the cordierite channels proceeds through positional disordering of the H2O sites inside the channel cavity and a stepwise filling of the H2O position inside the 6-membered rings, leading to the phase transition at about 4.7 GPa. The appearance of H2O molecules inside 6-membered rings prevents their contraction and even causes their slight enlargement along the a direction, apparently related to the orientation of H-bonds. This results in an anisotropic deformation of the unit cell and an increase of the a parameter in the HP phase at 4.9 GPa, as well as a decrease of linear compressibility along a upon the further compression up to 6 GPa (beta(a):beta(b):beta(c) = 5:9:10).
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| Ключевые слова: | BEHAVIOR; CHEMISTRY; SINGLE-CRYSTAL; MG-CORDIERITE; CRYSTAL-STRUCTURE; crystal structure; pressure-induced hydration; compressibility; high pressure; Cordierite; CO2; |
| Издано: | 2013 |
| Физ. характеристика: | с.181-186 |